Steam-boiler or other furnace.



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No. 702,756. f

(Application` led Mar. 5. 1902.)

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UNITED STATES PATENT OEEICE."`

WILLIAMF. `VVILMOTH, OF NEW YORK, N. Y., ASSIGNORgTO AMERICAN .FURNAOE OOMPAN-Y,OF-NEW,YORK, N. Y., A CORPORATION OF NEW YORK.' l

STAM-'BOILER 0R OTHER FURNACE.

SPECIFICATION forming part of Letters Patent No. 702,7 56, dated ,Tune 17.1902 Original application filed October 18, 1901, vSerial No. 79,176. Divided and this lapplication filed March 5, 1992. Serial Nm 96,851. (No man.)

T @ZZ whom, it may concern:

Be it known'that I, WILLIAM FRANKLIN WILMOTH, a citizen of the United States, residing inV New York,-in the county andState of New York, have invented certain new and useful Improvements in Steam-Boiler or other Furnaces; and Ido hereby declare the following lto be a fullyclear, and exact description of the invention, such as will enable others skilled in the' art to which it appertains to make/and use the same.

My lnvention relates to improvements in steam-boiler and other furnaces; and it consists in the novel means employed for admitting air to the furnace and heating such' air before contact thereof with the furnace-gases and 1n the novel construction of'an arch over:

the furnace. l t

The present applicationfor Letters Patent is a division of one filed by me on October 18,v 1901, Serial No. 79,176.

The objects of my invention are to increaserr the efficiency of boiler and other furnaces,to

avoid the production'of smoke when usingV bituminous coal and other smoke-producing fuel, to heat effcientlythe 'air suppliedto complete the combustion without decreasing the efficiency of any portion of the heating` I will now proceed todescribe Iny'inve'n-4r tion with reference 'to vthe accompanying drawings and will In the drawings, Figure l showsa longitudinal section of a water-tube boiler of the Babcock Wilcox type` employing longitudinal inclined generating-tubes, the furnace of which boilerisconstructed in accordanceV Y with my invention. vlig.L 2 is a horizontal chamber. construction.

then point out'the novel,` featuresin claims.

tion-chamber l, anash-'pit 2, with suitable fire-doors 3, ash-pit doors il, grate-bars 5, and a bridge-wall 6 at the rear of the combustion- These' parts'may be of ordinary The furnace has also the ordinary sidewalls 7. vAbove the furnace is an arch 8, the construction of which is broadly .claimed in V the said application for Letters Patent-filed, OctoberllO, 1901, Serial No.

79,17 6, of which this'is a division, although a particular feature of the' construction of the arch is claimed herein. lt has been common in the past to use arches ,over the combustionchambers offurnaces'; Abut such arches have usually been constructed of brick and have v given much trouble'byfallingwhile the furnace isin use.

n The-arch "of Vmy furnace is constructed of cantaliver-sections 9 9, of re- .clay ork other,suitableLmaterialgwhich in the ,case of furnaces of narrow or medium width may be set`V into the'side Walls 7, as illustrated and described inf Inyjsaid application SerialA `No. 79,176; butin the -case ofwide furnaces,

such as that illustrated inthe drawings of thisvcase, are preferably supported by skewback supports 59', forming continuations of the malin cantaliver-sections9,]composed of similar material andset into the side Walls. The reasonfor employing this construction in wide furnacesisthatl find it diflicult to obtain perfect and reliable arch-sections of a greater length than three feet.' The sections 9are preferably joined at the center, as by an ordinary tongue-and-groove joint.

the careless handling of ire-tools, as will a brick arch. I A l In order that space within the combustionchamber may be economized, particularly at the center, Where the 'most spaoel-is usually needed, and in order that the arch-sections Such f lvanarch is exceedinglystrong ,and will not be shaken down fby jar orbylvibration or by may have great strength in proportion to their thickness and weight, the said sections taper from their points of support at the sides to or nearly to the meeting-point at the center.

At the rear of the furnace there is the usual opening 10 for the escape of furnace-gases,

and at the front of the furnace there isanother and preferably smaller opening 11, the existence of which is important, since otherwise the efficiency of the front portion of the boiler mightberednced. 'Ihisisparticularly true with respect to the type of boiler illustrated, in which the heatingis effected mainly through the passage of the furnace-gases between and around the inclined generatingtubes 12 and along the under surface of the drum 13, the furnace for the sake of economy in space occupied being placed under the front portion of the boiler. In such boilers baffleplates 14 are customarily used to deflect the furnace-gases from the rear ot' the combustion-chamber to the front portions of the generating-tubes and drum, thus making the front portions of these tubes and of the drum elfective as heating-surface; yet in such boilers an arch over the combustionchamber must inevitably prevent contact of the furnace-gases with the extreme front portions of the generating-tubes, and particularly of the lower tubes, unless an opening, such as l1, through which a portion of the furnace-gases may pass to these front portions of the generating-tubes, is provided.

In the front of the furnace-Wall there is an air-flue l5, open at the ends. This flue communicates with fines in a projecting piece 16, which crosses the opening 11, so that air entering the flue 15 is discharged beneath but in close proximity to the lower portion of the arch and is caused to pass along the under surface of the arch, becoming heated as it does so, until it encounters the furnace-gases issuing through the opening 10 and assists in completing combustion in the furnace, and particularly in consuming the finely-divided particles of fuel, which otherwise might become smoke.

It is well known that if cold air be introduced into a furnace above the fuel perfect combustion may be interfered with rather than helped and the fire may be deadened; but I find the contrary to be the case when air, taken as above described, is highly heated, as above described, before encountering any considerable quantity of the furnacegases. Vhen such highly-heated air does encounter such gases, it aids materially in effecting complete combustion within the furnace.

Carrying the air from the flue l5 across the opening 1l by means of the ilues in the bloclr 16 prevents the air from becoming mixed at this point with the furnace-gases before the air has become highly heated. This block or projection also serves as a support for the arch. The sections 9 immediately above it rest upon it, and the adjacent sections are provided with inclined faces, so that the sections rest on one another, and thus the Weight of sections distant from the support is transferred thereto. In the same manner a corbelsupport 17, projecting from the bridge-wall, may be employed to support the arch at the rear. The width and depth of the combustion-chamber determine whether one or more central supports for the arch shall he employed.

In the operation of the furnace the air en tering through the flue 15 and projected along the under surface of the arch becomes highly heated, and then encountering the furnacegases issuing through the opening 10 it supplies to such gases a relatively fresh supply of oxygen at a temperature such that combustion is greatly promoted thereby, and thus the greater portion of the unconsumed or incompletely-consumed gases and particles of fuel which otherwise might pass out of the chimney without being completely consumed are burned. Because of the opening 11 between the arch and the front of the furnace the front portion of the boiler is adequately heated, and thereby an objection to the employment of brick arches as heretofore constructed is overcome.

It will be noted that the invention does not involve the use of long and small lines through the arch, which'are difficult to clean, nor does it involve the use of metal air-tubes, which are likely to be burned out. The air-fine in the front wall and the flues through the block 1G are relatively large and are easily cleaned by a steam-jet, and, moreover, the tendency of the air-current is to carry dust out of the fines rather than into them.

It is obvious that my invention is susceptible of many modifications in construction and arrangement of the parts and that many such modifications may be necessary to adapt it to furnaces of peculiar construction. I do not limit myself, therefore, to the particular details of construction and arrangement of parts herein illustrated and described.

-What I claim ism l. In a furnace, the combination With furnace walls, an arch over the combustionchamber, openings being provided at the front and rear of the arch for the escape of furnacegases, and a baffle-plate which directs forward and over the arch the furnace-gases es- ICO IIO

caping through the said rear opening, of an air-flue which admits air beneath the arch and directs it along the lower surface thereof.

2. In a furnace, the combination with furnace-walls, of an arch over the combustionchamber, an opening being provided at the front of the arch for the escape of a portion of the furnace-gases, and another opening being provided at the rear for the escape of thc remainder of the furnace-gases, an air-flue at one end of the combustion-chamber for admitting air to the furnace, and means spanning one of said openings and containing a flue forming a continuation of such air-line, for delivering air in the immediate vicinity of said arch.

3. In a furnace, the combination With furnace-walls, of an arch over the combustionchamber, an opening being provided at the front of the arch for the escape of a portion of the furnace-gases, and another opening l y 1|' l provided atthe rear for the escape of the furlmain canta1iver-sectionsextending from the y nace-gases, and a support for: the arch, spancenter to the ends of the'said skewbacks-but 'f y ning one of said openings, and containing'an not to said side walls, supported by said skewair-fine which admits air beneath the Aarch backs and joined at the center. 5 and directs it along the lower surfacethereof. In testimony whereof I afx my signature 15 4. In a furnace, the combination withfur- `in the presence of two witnesses.

nace-walls, of'an arch over the combustiony WILLIAM'F. WILMOTH; chamber comprising skewback supports sup- Witnesses: Y y .t t l' ported and projecting from the furnace-walls WILLIAM D. ADAM,

1o and forming part of the span ofthe arch, and HARRY M. MARBLE. 

